Watch Intently (one)oxcarbazepine will lower the level or effect of fentanyl by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Watch Carefully. Coadministration of fentanyl with CYP3A4 inducers may lead to some minimize in fentanyl plasma concentrations, lack of efficacy or, potentially, advancement of a withdrawal syndrome i… Read More